- Softwood (Nordic spruce): £15–£25/m² boards. Cheapest upfront — needs annual oiling or fails within 5 years.
- Pressure treated pine: £18–£30/m² boards. Lasts 10–15 years with oiling. Budget choice for maintained decks.
- Siberian larch: £45–£70/m² boards. Naturally durable, no treatment needed, 20–30 years. Best mid-budget whole-life choice.
- ThermoWood: £55–£85/m² boards. Zero maintenance, 25–40 years, secret fix available. Best premium specification.
- Yellow Balau hardwood: £65–£90/m² boards. Durability Class 1, 40–60 years, no treatment. Premium natural hardwood.
- Jatoba (Brazilian Cherry): £75–£105/m² boards. Hardest, most durable option available. 40–60 years above ground.
- Installation: £25–£45/m². Subframe, fixings, membrane: £8–£15/m². Total 20m² deck: £960–£3,300 fully installed.
The cost of timber decking in the UK varies more than almost any other garden project — from £15 per m² for basic softwood boards to over £100 per m² for premium tropical hardwood, with five distinct species categories sitting between those extremes. The upfront board price is only part of the picture. The species you choose determines not just what you pay now but what you pay over 20–30 years in maintenance, treatment, and eventual replacement. This guide gives you accurate 2026 pricing for every timber decking species we stock — boards, subframe, installation, and whole-life cost — so you can make the right choice for your budget and your project.
Hardwood decking boards — Yellow Balau and Jatoba from UK stock. Premium tropical hardwood decking at £65–£105 per m², naturally Durability Class 1 with a 40–60 year service life and no preservative treatment required.
Timber Decking Cost per m² — All Species at a Glance
| Species | Board cost/m² | Service life | Maintenance | Installed/m² | 20m² total |
|---|---|---|---|---|---|
| Nordic Spruce | £15–£25 | 5–10 yrs untreated | Oil annually | £48–£85 | £960–£1,700 |
| Pressure Treated Pine | £18–£30 | 10–15 yrs | Oil annually | £51–£90 | £1,020–£1,800 |
| Siberian Larch | £45–£70 | 20–30 yrs | None required | £78–£130 | £1,560–£2,600 |
| ThermoWood | £55–£85 | 25–40 yrs | Zero — ever | £88–£145 | £1,760–£2,900 |
| Yellow Balau | £65–£90 | 40–60 yrs | Minimal — oil optional | £98–£150 | £1,960–£3,000 |
| Jatoba / Brazilian Cherry | £75–£105 | 40–60 yrs | Minimal — oil optional | £108–£165 | £2,160–£3,300 |
All installed costs include boards, C16 treated softwood subframe timber, A4 stainless fixings, joist hangers, weed membrane, and professional installation. They exclude VAT (20% on labour for residential), scaffolding (not required for ground-level decks), and any groundworks or structural engineering.
Softwood Decking Cost UK 2026 — Nordic Spruce & Pressure Treated Pine
Softwood decking is the cheapest upfront option and the most widely sold decking material in the UK. Nordic spruce and pressure treated pine both sit in the £15–£30 per m² range for boards — roughly a third of the cost of Siberian larch and less than a quarter of premium hardwood. The low upfront cost makes softwood the default choice for many homeowners — but it comes with a maintenance obligation that significantly changes the whole-life cost calculation.
Nordic spruce — £15–£25 per m² boards
Nordic spruce is Durability Class 4–5 — it has virtually no natural resistance to biological decay. Left untreated outside, it will deteriorate within 3–5 years in UK conditions. It must be treated with preservative oil annually from the year of installation. Miss two consecutive years of treatment and the surface begins to fail — grey splitting fibres, surface cracking, and eventual structural softening. For a deck you will reliably maintain every year, spruce is a cost-effective choice. For a deck you might occasionally neglect, it is a false economy.
Pressure treated pine — £18–£30 per m² boards
Pressure treated pine decking has a preservative compound forced into the timber under vacuum pressure at the factory, giving it significantly better initial biological resistance than untreated spruce. The green tint of fresh pressure treated timber fades to a natural grey over time. It still requires annual oiling to maintain the surface and slow UV degradation — but the treatment provides a safety margin if a year's maintenance is missed. Service life 10–15 years with consistent treatment. This is the standard budget specification for residential garden decking in the UK.
A softwood deck on a raised structure or house-adjacent position that requires a ladder or scaffolding for maintenance will cost £200–£600 in access equipment every time it needs treating. At annual treatment cycles over 15 years, that access cost can exceed the original board cost. For any deck above approximately 1.5m that requires safe access for maintenance, a naturally durable species (larch or ThermoWood) is almost always cheaper whole-life.
Siberian Larch Decking Cost UK 2026 — Naturally Durable, No Treatment
Siberian larch decking costs £45–£70 per m² for boards — approximately three times the cost of softwood upfront, but with a fundamentally different whole-life cost profile. Larch is naturally Durability Class 3 (Moderately Durable under BS EN 350) — it requires no preservative treatment for above-ground deck use throughout its 20–30 year service life.
The practical implication: the board purchase is essentially the total cost of ownership. No annual oiling required, no preservative treatment, no scaffolding for maintenance on raised decks. Optional oiling every 2–3 years with Koopmans Houtolie will maintain the warm honey-gold colour — but if you prefer the natural silver-grey weathered appearance, no treatment is ever needed.
| Larch decking profile | Dimensions | Board cost/m² | Fix method |
|---|---|---|---|
| Smooth 28x140mm | 28 x 140mm | £45–£58 | Face fix |
| Ribbed 27x142mm | 27 x 142mm | £48–£62 | Face fix — anti-slip |
| Grooved 28x140mm | 28 x 140mm | £52–£68 | Face fix — grooved surface |
| Batten 45x70mm | 45 x 70mm | £55–£70 | Face fix — narrow board look |
ThermoWood Decking Cost UK 2026 — Zero Maintenance Premium
ThermoWood decking costs £55–£85 per m² for boards — the premium softwood-based specification and the highest-performing low-maintenance option available. ThermoWood is thermally modified Scots pine heated to 190–212°C, permanently altering the timber's cell structure to achieve Durability Class 2 (Durable) — the same class as oak — with zero chemical treatment. This means no preservative oil is ever required, the surface will not rot, and the service life is BRE endorsed at 30 years.
The secret fix profiles — grooved boards used with Brofix hidden decking fasteners — produce a completely clean deck face with no visible fixings. This is the premium finish that architects and homeowners increasingly specify for contemporary outdoor spaces.
| ThermoWood profile | Dimensions | Board cost/m² | Fix method |
|---|---|---|---|
| Face Fix 26x117mm | 26 x 117mm | £55–£65 | Face fix |
| Secret Fix Grooved 26x117mm | 26 x 117mm | £60–£72 | Brofix hidden fix |
| Secret Fix Smooth 26x140mm | 26 x 140mm | £65–£78 | Brofix hidden fix |
| Secret Fix Brushed 26x140mm | 26 x 140mm | £68–£85 | Brofix hidden fix |
Hardwood Decking Cost UK 2026 — Balau, Jatoba & Angelim
Hardwood decking represents the premium end of the UK decking market — boards costing £65–£105 per m², but with a service life of 40–60 years and Durability Class 1 (Very Durable) natural resistance that requires no preservative treatment. The three hardwood species we stock offer different performance and aesthetic profiles:
Yellow Balau (Bangkirai) — £65–£90 per m²
Yellow Balau is the most widely specified tropical hardwood decking in the UK — dense, stable, naturally Durability Class 1, and available in three profiles: smooth 21x145mm, ribbed 21x145mm, and dual ribbed 25x145mm. The warm golden-brown tone weathers gracefully, and the high density provides excellent natural slip resistance on the ribbed and dual ribbed profiles. The most cost-effective hardwood specification at £65–£90 per m² with a 40–60 year service life.
Jatoba — Brazilian Cherry — £75–£105 per m²
Jatoba (Brazilian Cherry) is one of the hardest and most durable naturally occurring decking timbers available — Janka hardness rating approximately 1,260 lbf, significantly harder than oak. The deep reddish-brown colour and exceptional density make it the premium residential hardwood decking specification. Smooth profile 21x145mm available from UK stock. Service life 40–60 years, no treatment required.
Angelim Amargoso / Angelim Pedra — Contact for pricing
Angelim is a genus of South American hardwood that includes some of the most durable timber species available — Class 1 durability, exceptional density, and a distinctive grain character. Available in smooth profile from UK stock. Contact our team for current pricing as this species fluctuates more than the established hardwood lines.
| Hardwood species | Durability class | Board cost/m² | Service life | Treatment |
|---|---|---|---|---|
| Yellow Balau (Bangkirai) | Class 1 — Very Durable | £65–£90 | 40–60 yrs | None required |
| Jatoba — Brazilian Cherry | Class 1 — Very Durable | £75–£105 | 40–60 yrs | None required |
| Angelim Amargoso/Pedra | Class 1 — Very Durable | POA | 40–60 yrs | None required |
What the Installation Cost Includes — and What It Doesn't
The installed costs quoted throughout this guide include:
- Decking boards at the quoted per-m² rate
- C16 pressure treated softwood joists at 400mm centres
- C16 treated perimeter frame
- Adjustable steel post bases or concrete footings (ground level)
- Joist hangers and structural fixings
- A4 stainless steel decking screws or Brofix secret fix clips
- Weed membrane — full deck footprint
- Professional installation labour — 2-person team
They do not include: VAT (20% on residential labour); steps, balustrade or lighting; removal of existing decking (£8–£15/m² additional); scaffolding for elevated decks; structural engineering for raised structures over 600mm; or landscape works around the completed deck.
Whole-Life Cost — The Number That Changes the Decision
The upfront cost comparison almost always favours softwood. The 30-year whole-life cost comparison almost always favours larch, ThermoWood, or hardwood. The difference is maintenance — specifically the annual oiling cost and, for elevated decks, the access cost for that maintenance.
| Species | Boards + install/m² | 30-yr maintenance/m² | 30-yr whole-life/m² | Replacements needed |
|---|---|---|---|---|
| Nordic Spruce | £48–£85 | £60–£120 (annual oil) | £108–£205 + 1–2 replacements | 1–2 over 30 years |
| Pressure Treated Pine | £51–£90 | £45–£90 (annual oil) | £96–£180 + 1 replacement | 1 over 30 years |
| Siberian Larch | £78–£130 | £0–£15 (optional oil) | £78–£145 | None |
| ThermoWood | £88–£145 | £0 | £88–£145 | None |
| Yellow Balau | £98–£150 | £0–£10 (optional oil) | £98–£160 | None |
The whole-life cost of Siberian larch decking on a typical 20m² deck is broadly comparable to treated softwood once annual oiling and a single replacement are factored in — the larch crossover point is approximately 8–12 years. ThermoWood's crossover with treated softwood is approximately 6–10 years. After that crossover point, every year of a larch or ThermoWood deck is effectively free maintenance versus a softwood deck that keeps accruing treatment costs. For a deck you plan to keep for 15+ years, a naturally durable or modified species is the rational financial choice — not just the quality choice.
Total Deck Cost by Project Size — 2026
| Deck size | Spruce installed | Larch installed | ThermoWood installed | Hardwood installed |
|---|---|---|---|---|
| Small — 10m² | £480–£850 | £780–£1,300 | £880–£1,450 | £980–£1,650 |
| Typical — 20m² | £960–£1,700 | £1,560–£2,600 | £1,760–£2,900 | £1,960–£3,300 |
| Large — 30m² | £1,440–£2,550 | £2,340–£3,900 | £2,640–£4,350 | £2,940–£4,950 |
| Wraparound — 50m² | £2,400–£4,250 | £3,900–£6,500 | £4,400–£7,250 | £4,900–£8,250 |
Regional Price Variation — London vs Rest of UK
Board prices are consistent nationally — we supply at the same price from March, Cambridgeshire regardless of delivery location. Labour varies significantly by region:
| Region | Installation labour/m² | vs Midlands baseline |
|---|---|---|
| London | £35–£55 | +25–35% |
| South East | £30–£48 | +15–25% |
| Midlands / East Anglia | £25–£38 | Baseline |
| North of England | £22–£35 | −5–10% |
| Scotland / Wales | £22–£36 | −5–10% |
What Affects the Cost of Decking — Beyond the Species
- Profile and fixing method: Secret fix (Brofix) adds 10–15% to installation time versus face fix. Wide boards (140mm+) require slightly fewer linear metres per m² but cost more per board. Ribbed profiles cost the same as smooth in most species
- Elevated decks: Any deck over 600mm requires balustrade (building regulations). Decks over 300mm require planning permission assessment. Both add cost — balustrade from £150–£400 per linear metre depending on specification
- Ground preparation: Sloped gardens requiring post-supported subframes add £200–£600 over flat-ground construction. Rocky or clay ground requiring mechanical excavation adds further
- Steps: Each set of steps adds £200–£600 depending on width and species. Allow for at least one step set in most standard garden decks
- Waste allowance: Add 10% to board quantity for cutting waste on simple rectangular decks. Add 15% for complex shapes, diagonal laying, or pattern boards
The most reliable way to get an accurate deck cost is to tell us your deck dimensions, the species and profile you want, and whether steps or balustrade are required. We calculate the exact board quantity, subframe timber, and fixings needed — and produce a complete material list with everything your installer needs. Contact our team or use the quote request form for a response within 1 working day.
How much does timber decking cost per m² in the UK?
Timber decking costs £15–£105 per m² for boards depending on species. Softwood £15–£30/m², Siberian larch £45–£70/m², ThermoWood £55–£85/m², hardwood balau and jatoba £65–£105/m². Add £8–£15/m² for subframe and fixings and £25–£45/m² for professional installation. Total installed costs for a 20m² deck range from £960 (softwood) to £3,300 (premium hardwood).
What is the cheapest timber decking in the UK?
Nordic spruce is cheapest upfront at £15–£25/m² for boards. Pressure treated pine is slightly more at £18–£30/m² but lasts significantly longer. Both require annual oiling — over 20 years an unmaintained softwood deck needs replacing, making larch cheaper whole-life despite triple the upfront cost.
How much does ThermoWood decking cost per m²?
ThermoWood decking costs £55–£85/m² for boards in 2026. Face fix at the lower end, secret fix brushed profiles at the higher end. Total installed cost for a 20m² deck approximately £1,760–£2,900. Zero maintenance for 25–40 years — no oiling, no treatment, no replacement.
How much does hardwood decking cost in the UK?
Yellow Balau (Bangkirai) hardwood decking costs £65–£90/m² for boards. Jatoba (Brazilian Cherry) costs £75–£105/m². Both are Durability Class 1 with a 40–60 year service life and no treatment required. Total installed cost for a 20m² deck approximately £1,960–£3,300.
How much does it cost to build a 20m² deck in the UK?
A 20m² garden deck costs approximately: softwood £960–£1,700 fully installed; Siberian larch £1,560–£2,600; ThermoWood £1,760–£2,900; Yellow Balau hardwood £1,960–£3,000; Jatoba £2,160–£3,300. Add 20% VAT on labour. London and South East add 25–35% to installation cost.
Is ThermoWood decking worth the extra cost?
For most garden decks intended to last 15+ years, yes. The upfront premium over pressure treated softwood is approximately £700–£1,200 on a 20m² deck. The 30-year maintenance saving (no annual oiling, no replacement) is typically £1,500–£3,000 on a ground-level deck — more on elevated decks where access equipment adds cost. ThermoWood typically pays back its premium within 8–10 years.
Decking Boards — All Species from UK Stock
We supply softwood, Siberian larch, ThermoWood, and hardwood decking boards from UK stock. Tell us your deck dimensions and we'll calculate the precise board quantity, subframe timber, and fixings needed — complete material list with everything your installer needs. Nationwide delivery 7–14 days.